Polyblends of chemically joined, phase separated thermoplastic graft copolymers

ABSTRACT

The present invention relates to polyblends of at least one polymer blended with thermoplastic graft copolymers comprised of copolymeric backbones containing a plurality of uninterrupted repeating units of the backbone polymer and at least one integrally copolymerized moiety per backbone polymer chain having chemically bonded thereto a substantially linear polymer which forms a copolymerized sidechain to the backbone, wherein each of the polymeric sidechains has substantially the same molecular weight and each polymeric sidechain is chemically bonded to only one backbone polymer.

United States Patent 1 Milkovich et al.

[ Apr. 22, 1975 POLYBLENDS OF CHEMICALLY JOINED,

PHASE SEPARATED THERMOPLASTIC GRAFT COPOLYMERS [75] Inventors: RalphMilkcvich, Naperville;

Mutong T. Chiang, Palos Heights; Gerald O. Schulz, Downers Grove.

all of I11.

[73] Assignee: CPC International Inc., Englewood Cliffs, NJ.

[22] Filed: Jan. 14, 1974 [21] Appl. No.: 433,314

Related US. Application Data [60] Division of Ser. No. 282,099, Aug. 21,1972, Pat. No. 3,786.1 16, which is a continuation-in-part of Ser. No.2441205, April 14, 1972, Pat. No. 3,832,423, which is acontinuation-in-part of Ser. No. 1l7 733, Feb. 22. 1971. abandoned.

[58] Field of Search 260/876 R, 878. 880

[56] References Cited UNITED STATES PATENTS 3.235.626 2/1966 Waack260/881 Webb..... 260/836 Simms et a1. 260/22 CB OTHER PUBLICATIONSGreber, U. G., Ueber den Aut'bau von Block-und Pfropfcopolymeren, DieMakromozekuzare Chemie, 101 pp. 104-144, (1967).

Black et al., The Preparation of Some Block Copolymers," Journal ofApplied Polymer Science, 14 pp. 1671-1677 (1970).

Primary Examinen-Murray Tillman Assistant Examiner-C. J. SeccuroAttorney, Agent, or FirmAlbert P. Halluin 571 ABSTRACT The presentinvention relates to polyblends of at least one polymer blended withthermoplastic graft copolymers comprised of copolymeric backbonescontaining a plurality of uninterrupted repeating units of the backbonepolymer and at least one integrally copolymerized moiety per backbonepolymer chain having chemically bonded thereto a substantially linearpolymer which forms a copolymerized sidechain to the backbone, whereineach of the polymeric sidechains has substantially the same molecularweight and each polymeric sidechain is chemically bonded to only onebackbone polymer.

20 Claims, No Drawings This application is a division of applicationSer. No. 282,099. filed Aug. Zl. 1972, now US. Pat. No. 3.786.116.granted Jan. 15, 1974. which in turn is a continuation-in-part ofapplication Ser. No. 244,205.

Lil

filed Apr. 14. 1972. now U.S. Pat. No. 3,832,423..

granted Aug. 27. 1974. which in turn is a continuationin-part ofapplication Ser. No. 1 17.733. filed Feb. 22. l97l. now abandoned.

BACKGROUND OF THE INVENTION a. Statement Of The Invention The presentinvention relates to polyblends of at least one polymer blended withchemically joined. phase separated thermoplastic graft copolymers.

b. Description Of The Prior Art Polymer technology has developed to ahigh degree of sophistication and extensive research efforts in thisdirection are being undertaken to obtain improvements in polymerproperties. Some of these efforts lead to polymer materials capable ofcompeting with metals and ceramics in engineering applications.Generally, it is a requirement that these polymers be crystalline. sincecrystalline polymers are strong. tough. stiff and generally moreresistant to solvents and chemicals than their non-crystallinecounterparts.

Many poly alpha-olefins are crystalline and have excellent structuralintegrity; and. accordingly. have acquired increasing commercialacceptance as materials for competing with metals and ceramics. As oneexample. polyethylene has been regarded as one of the most importantpolymers among the major plastics. with its production reaching about 6billion pounds in 1970 (L7 billion pounds of high density linearpolyethylene and 4.3 billion pounds of low density polyethylene).

Despite the widespread use of this important plastic, its use has beenlimited to flexible, translucent. molded articles or flexible. clearfilms. due to its softness. The uses of polyethylene have also beenlimited due to its poor adhesion to many substrates and its low heatdistortion. rendering it unsuitable for many high temperatureapplications.

Attempts by prior art workers to combine the properties of polyolefmsand other polymers by either chemical or mechanical means generally hasresulted in a sacrifice of many of the beneficial properties of both thepolyolefin and the additional polymer. For example, graft copolymers ofpolyethylene and polypropylene have been prepared only with difficultydue to the inertness these polymers have with many other polymerizablemonomers and polymers. The resultant graft copolymer generally has beena mixture which also contains free homopolymers.

Polyblends of a polyolefin with another polymer prepared by blendingquantities of the two polymers together by mechanical means have beengenerally unsuitable for many applications due to their adversesolubility or extractability properties when used with various solventsystems. particularly when containing a rubbery, amorphous component.

The above considerations recognized by those skilled in the art withrespect to the incompatibility of polyolefins with other polymers findalmost equal applicability in the case of other plastics such as thepolyacrylates.

polymethacrylates. polyvinylchlorides, etc. Thus. the incompatibility ofboth natural and synthetic polymers becomes increasingly apparent asmore and more polymers having particularly good properties for specialuses have become available, and as efforts have been made to combinepairs of these polymers for the purpose of incorporating the different,good properties of each polymer into one product. More often than not.these efforts have been unsuccessful because the resulting blends haveexhibited an instability, and in many cases the desirable properties ofthe new polymers were completely lost. As a specific example,polyethylene is incompatible with polystyrene and a blend of the two haspoorer physical properties than either of the homopolymers. Thesefailures were at first attributed to inadequate mixing procedures, buteventually it was concluded that the failures were due simply to theinherent incompatibilities. Although it is now believed that this is acorrect explanation, the general nature of such incompatibility hasremained somewhat unclear. even to the present. Polarity seems to be afactor. i.e.. two polar polymers are to be more compatible than a polarpolymer and a non-polar polymer. Also, the two polymers must bestructurally and compositionally somewhat similar if they are to becompatible. Still further. a particular pair of polymers may becompatible only within a certain range of relative proportions of thetwo polymers; outside that range they are incompatible.

Despite the general acceptance of the fact of incompatibility of polymerpairs. there is much interest in devising means whereby the advantageousproperties of combinations of polymers may be combined into one product.

One way in which this objective has been sought involves the preparationof block or graft copolymers. In this way. two different polymericsegments. normally incompatibile with one another. are joined togetherchemically to give a sort of forced compatibility. In such a copolymer,each polymer segment continues to manifest its independent polymerproperties. Thus. the block or graft copolymer in many instancespossesses a combination of properties not normally found in ahomopolymer or a random copolymer.

Recently, US. Pat. No. 3,235,626 to Waack, assigned to Dow ChemicalCompany, described a method for preparing graft copolymers of controlledbranch configuration. It is described that the graft copolymers areprepared by first preparing a prepolymer by reacting a vinyl metalcompound with an olefinic monomer to obtain a vinyl terminatedprepolymer. After protonation and catalyst removal. the prepolymer isdissolved in an inert solvent with a polymerization catalyst and isthereafter reacted with either a different polymer having a reactivevinyl group or a different vinyl monomer under free-radical conditions.

The current limitations on the preparation of these copolymers aremechanistic. Thus, there is no means for controlling the spacing of thesidechains along the backbone chain and the possibility of thesidechains having irregular sizes. due to the mechanistic limitations ofthe prior art methods. i.e., the use of an alphaolefin terminatedprepolymer with acrylonitrile or an acrylate monomer. complicatedmixtures of free homopolymers result.

In view of the above considerations. it would be highly desirable todevise a means for preparing graft copolymers wherein the production ofcomplicated mixtures of free homopolymers is minimized and thebeneficial properties of the sidechain and backbone polymer are combinedin one product.

Moreover, it is recognized and documented in the literature, such as R.Waack et al, Polymer, Vol. 2, pp. 365-366 (1961), and R. Waack et a], J.Org. Chem.. Vol. 32, pp. 3395-3399 (1967), that vinyl lithium is one ofthe slowest anionic polymerization initiators. The slow initiatorcharacteristic of vinyl lithium when used to polymerize styrene producesa polymer having a broad molecular weight distribution due to the ratioof the overall rate of propagation of the styryl anion to that of thevinyl lithium initiation. In other words, the molecular weightdistribution of the polymer produced will be determined by the effectivereactivity of the initiator compared with that of the propagatinganionic polymer species, i.e., vinyl lithium initiator reactivitycompared to the styryl anion. Accordingly, following the practice of US.Pat. No. 3,235,626, a graft copolymer having sidechains of uniformmolecular weight cannot be prepared.

US. Pat. Nos. 3,390,206 and 3,514,500 described processes forterminating free-radical and ionic polymerized polymers with functionalgroups which are described as capable of copolymerizing withpolymerizable monomers. The functionally terminated prepolymersdescribed by these patentees also would be expected to have a broadmolecular weight distribution and, therefore, would not be capable ofproducing a chemically joined, phase separated thermoplastic graftcopolymer.

SUMMARY OF THE INVENTION The present invention relates to one polymerblended with polyblends of at least thermoplastic graft copolymerscomprised of copolymeric backbones containing a plurality ofuninterrupted repeating units of the backbone polymer and at least oneintegrally copolymerized moiety per backbone polymer chain havingchemically bonded thereto a substantially linear polymer which forms acopolymerized sidechain to the backbone, wherein each of polymericsidechains has substantially the same molecular weight and eachpolymeric sidechain is chemically bonded to only one backbone polymer.

The graft copolymers useful in preparing the polyblends of the presentinvention assume a T type structure when only one sidechain iscopolymerized into the copolymeric backbone. However, when more than onesidechain is copolymerized into the backbone polymer, the graftcopolymer may be characterized as having a comb-type structureillustrated in the following manner:

n-n-e n--a--n ties of at least one of the substantially linear polymers,

are manifest; b represents a reacted and polymerized end groupchemically bonded to the sidechain, a, which is integrally polymerizedinto the backbone polymer, and c is the backbone polymer havinguninterrupted segments of sufficient molecular weight such that thephysical properties of the polymer are manifest.

The backbone of the graft copolymers useful in preparing the polyblendsof the present invention preferably contains at least about 20uninterrupted recurring monomeric units in each segment. it has beenfound that this condition provides the graft copolymer the properties ofthe polymer. In other words, the presence of segments containing'atleast about 20 uninterrupted recurring monomeric units provides thegraft copolymers with the physical properties attributed to thispolymer, such as'crystalline melting points (Tm) and structuralintegrity.

The backbone polymeric segments of the chemically joined, phaseseparated thermoplastic graft copolymers of the present invention arederived from copolymerizable monomers, preferably the low molecularweight monomers. These copolymerizable monomers include polycarboxylicacids, their anhydrides and amides, polyisocyanates, organic epoxides,including the thioepoxides, urea-formaldehydes, siloxanes, andethylenically unsaturated monomers. A particularly preferred group ofcopolymerizable monomers include the ethylenically-unsaturated monomers,especially the monomeric vinylidene type compounds, i.e., monomerscontaining at least one vinylidene group. The vinyl type compoundsrepresented by the formula wherein a hydrogen is attached to one of thefree valences of the vinylidene group are contemplated as falling withinthe generic scope of the vinylidene compounds referred to hereinabove.

The copolymerizable monomers useful in the practice of the presentinvention are not limited by the exemplary classes of compoundsmentioned above. The only limitation on the particular monomers to beemployed is their capability to copolymerize with the polymerizable endgroups of the sidechain prepolymer under free-radical, ionic,condensation, or coordination (Ziegler or Ziegler-Natta catalysis)polymerization reactions. As it will be seen from the description ofmacromolecular monomers, described hereinbelow, the choice ofpolymerizable end groups includes any polymerizable compoundcommercially available. Accordingly. the choice of respectivepolymerizable end group and copolymerizable monomer can be chosen, basedupon relative reactivity ratios under the respective copolymerizationreaction conditions suitable for copolymerization reaction. For example,alpha-olefins copolymerize with one another using Ziegler catalysts, andacrylates copolymerize with vinyl chloride, acrylonitrile and otheralkyl acrylates. Accordingly, an alphaolefin terminated macromolecularmonomer copolymerizes with ethylene and alpha-olefins using a Zieglercatalyst and an acrylate or methacrylate terminated macromolecularmonomer copolymerizes with vinyl chloride, acrylonitrile, acrylates andmethacrylates under free-radical conditions in a manner governed by therespective reactivity ratios for the comonomers.

As will be explained hereinafter, the excellent combination ofbeneficial properties possessed by the graft copolymers of the presentinvention are attributed to the large segments of uninterruptedcopolymeric backbones and the integrally copolymerized linear side-'chains of controlled molecular weight and narrow molecular weightdistribution.

The term linear," referred to hereinabove, is being used in itsconventional sense, to pertain to a polymeric backbone that is free fromcross-linking.

The sidechain polymers having substantially uniform molecular weight arecomprised of substantially linear polymers and copolymers produced byanionic polymerization of any anionically polymerizable monomer, as willbe described hereinafter. Preferably, the sidechain polymer will bedifferent than the backbone polymer.

It is preferred that at least one segment of the sidechain polymer ofthe graft copolymers of the present invention have a molecular weightsufficient to manifest the beneficial properties of the respectivepolymer. In other words, physical properties of the sidechain polymersuch as the glass transition temperature (Tg) will be manifest.Generally, as known in the art, the average molecular weight of thesegment of the polymeric sidechain necessary to establish the physicalproperties of the polymer will be from about 5,000 to about 50,000.

In light of the unusual and improved physical properties possessed bythe thermoplastic graft copolymers of i the present invention, it isbelieved that the monofunctionally bonded polymeric sidechains havingsubstantially uniform molecular weight form what is known as *domains ofthe respective sidechain polymers from separate backbone copolymers.

STATEMENT OF THE INVENTION The present invention relates to polyblendscompris- A. from about 1 to about 50 parts by weight of a chemicallyjoined, phase separated thermoplastic graft copolymer comprising:

1. from about 1 percent to about 95 percent by weight of polymerizablemacromolecular monomers having a substantially uniform molecular weightdistribution, and

2. from about 99 percent to about 5 percent by weight of acopolymerizable comonomer forming the polymeric backbones of said graftcopolymer and said polymerizable macromolecular monomers forming linearpolymeric sidechains of said graft copolymer, wherein:

a. the polymeric backbones of the graft copolymer are comprised ofpolymerized units of said copolymerized comonomer, said copolymerizablecomonomer being at least one ethylenically unsaturated monomer andmixtures thereof:

b. the linear polymeric sidechains of the graft copolymer are comprisedof copolymerized macromolecular monomers, said macromolecular monomercomprising a linear polymer or copolymer having a molecular weight inthe range from about 5,000 to about 50,000 and having a substantiallyuniform molecular weight distribution, such that their ratio of Mw/Mn isless than about 1.1, said macromolecular being further characterized ashaving no more than one polymerizable moiety per linear polymer ofcopolymer chain, said copolymerization occurring between thepolymerizable end group of said macromolecular monomers and saidcopolymerizable comonomer; and

. the linear polymeric sidechains of the graft copolymer which arecopolymerized into the copolymeric backbone are separated by at leastabout 20 uninterrupted recurring monomeric units of said backbonepolymer, the distribution of 'the sidechains along the backbone beingcontrolled by the reactivity ratios of the polymerizable end group onsaid macromolecular monomers and said copolymerizable comonomer; andblended with B. from about 99 to about 50 parts by weight of at leastone other polymer.

Preferred polyblends of the present invention includes blends containingfrom about 1 to about 50 parts by weight of the aforedescribedchemically joined, phase separated thermoplastic graft copolymer. andfrom 99 to about 50 parts by weight of a polymer selected from the groupconsisting of a polymer of vinyl chloride, methyl methacrylate andacrylonitrile and copolymers thereof, and mixtures thereof, as well aspolymers of styrene and styrene-acrylonitrile copolymers, polymers ofethylene, propylene and copolymers thereof, and polymers and copolymersof conjugated dienes.

Briefly, the chemically joined, phase separated thermoplastic graftcopolymers of the present invention are prepared by first preparing thesidechains in the form of monofunctional living polymers ofsubstantially uniform molecular weight. The living polymers arethereafter terminated, as by reaction with a halogencontaining compoundthat also contains a reactive DESCRIPTION OF THE PREFERRED EMBODIMENTSThe chemically joined, phase separated thermoplastic graft copolymersderived from ethylenically unsaturated monomers as the backbonecomonomer generally correspond to the following structural formula:

il hl wherein R and R" are each selected from the group consisting ofhydrogen, lower alkyl, cycloalkyl, and aryl radicals; X and X are eachselected from the group consisting of hydrogen, alkylene radicals (i.e.,[CH x is a positive integer wherein the terminal methylene group in X iseither hydrogen, lower alkyl, e.g., methyl, halogen, etc., and in thecase of X, joins the backbone polymer with the sidechain polymer), asaturated ester (i.e.,

0 0 i -C -OR or 0-C-R wherein R is alkyl or aryl), nitrile (i.e., -C N),amide (i.e.,

. I 5 if -c -u \RII wherein R and R are either hydrogen, alkyl or arylradicals), amine (i.e.,

wherein R and R" are either hydrogen, alkyl or aryl radicals),isocyanate, halogen (i.e., F, Cl, Br or I) and either (i.e., -OR,wherein R is either alkyl or aryl radicals); X and X may be the same ordifferent. However, in the case where X is an ester, X should be afunctional group such as ester, halogen, nitrile, etc., as explainedhereinabove with respect to the respective reactivity ratios of thecomonomers used to prepare the graft copolymers; Y is a substantiallylinear polymer or copolymer wherein at least one segment of the polymerhas a sufficient molecular weight to manifest the properties of therespective polymer, i.e., a molecular 25 weight of from about 5,000 toabout 50,000, preferably a molecular weight of from about 10,000 toabout 35,000, more preferably l2,000 to about 25,000; the symbols (1, band c are positive integers, with the proviso that a and b are each avalue such that the physical properties of the uninterrupted segments inthe back-,

bone, e.g., Tm, are manifest, preferably at least about 20; and thesymbol c is at least one, but preferably greater than one, e.g., a valuesuch that the molecular weight of the graft copolymer will be up toabout 2,000,000. 7

The formation of the graft copolymers of the present invention may bebetter understood by reference to the following reactions illustrated bythe equations set forth below wherein the invention is illustrated interms of polystyrene sidechains and polyethylene backbones. It can beseen from these equations that the first reactions involve thepreparation of living polymers of polystyrene. The living olymers arethereafter reacted with a molar equivalent of allyl chloride, whereinthe reaction takes place at the carbon-chloride bond, rather than at thecarbon-carbon double bond. The vinyl terminated polystyrene, referred toherein as the alpha olefin terminated macromolecular monomer, is thencopolymerized with ethylene to produce a graft copolymer ofpolyethylene, whereby the vinyl moiety of the polystyrene is integrallypolymerized into the linear polyethylene backbone.

Alternatively, the living polymer can be reacted with an epoxide suchas, for example, ethylene oxide, to produce an alkoxide ion which canthen be reacted with the halogen-containing olefin, i.e., allylchloride, to produce an alpha-olefin terminated macromolecular monomer.This, in essence, places the terminal alphaolefin farther away from thearomatic ring of the polystyrene and therefore reduces any sterichindering influence that might be exerted by the aromatic ring.

Initiation: CH CH (CH )Cfll-1 C21 I ft! Propagation:

CH3CHZ(CHB)CH Termination with Active End Grgug:

V CH CH 2 (CR )C Craft: Copolymerization:

a z a CH I CHCH CI ll CH CH CH CH LQCI XCH CH Polymerization Catalyst Inthe equations above, the symbols a, b, c. n and X are positive integerswherein a and b are at least about 20, n has a value of from about 50 toabout 500, and X has a value corresponding approximately to the sum of aand b.

PREPARATION OF THE LIVING POLYMERS The sidechains of the chemicallyjoined, phase separated graft copolymers, above, are preferably preparedby the anionic polymerization of a polymerizable monomer of combinationof monomers. In most instances, such monomers are those having anolefinic group, such as the vinyl containing compounds, although theolefinic containing monomers may be used in combination with epoxy orthioepoxy containing compounds. The living polymers areconveniently-prepared by contacting the monomer with an alkali metalhydrocarbon or alkoxide salts in the presence of an inert organicdiluent which does not participate in or interfere with thepolymerization reaction.

Those monomers susceptible to anionic polymerization are well-known andthe present invention contemplates the use of all anionicallypolymerizable monomers. Non-limiting illustrative species include vinylaromatic compounds, such as styrene, alphamethylstryene, vinyl tolueneand its isomers; vinyl unsaturated amides such as acrylamide,methacrylamide, N,N-dilower alkyl acrylamides, e.g., N,N-dimethylacrylamide; acenaphthalene; 9- acrylcarbazole; acrylonitrile andmethacrylonitrile; organic isocyanates including lower alkyl, phenyl,lower alkyl phenyl are halophenyl isocyanates, organic diisocyanatesincluding lower alkylene, phenylene and tolylene diiocyanates; loweralkyl and allyl acrylates and methacrylates, including methyl, t-butylacrylates and methacrylates; lower olefins, such as ethylene, propylene,butylene, isobutylene, pentene, hexene, etc., vinyl esters of aliphaticcarboxylic acids such as vinyl acetate, vinyl propionate, vinyl octoate,vinyl oleate, vinyl stearate. vinyl benzoate, vinyl lower alkyl ethers;vinyl pyridines, vinyl pyrrolidones; dienes including isoprene andbutadiene. The term lower is used above to denote organic groupscontaining eight or fewer carbon atoms. The preferred olefiniccontaining monomers are conjugated dienes containing 4 to 12 carbonatoms per molecule and the vinyl-substituted aromatic hydrocarbonscontaining up to about 12 carbon atoms.

Many other monomers suitable for the preparation of the sidechains byanionic polymerization are those disclosed in Macromolecular Reviews:Volume 2, pages 7483, lnterscience Publishers, Inc. (I967), entitledMonomers Polymerized by Anionic Initiators, the disclosure of which isincorporated herein by reference.

The initiators for these anionic polymerizations are any alkali metalhydrocarbons and alkoxide salts which produce a monofunctional livingpolymer, i.e, only one end of the polymer contains a reactive anion.These catalysts found suitable include the hydrocarbons of lithium,sodium or potassium as represented by the formula RMe wherein Me is analkali metal such as so dium, lithium or potassium and R represents ahydrocarbon radical, for example, an alkyl radical containing up toabout carbon atoms or more, and preferably up to about eight carbonatoms. an aryl radical, an alkaryl radical or an aralkyl radical.Illustrative alkai metal hydrocarbons include ethyl sodium, n-propylsodium, n-butyl potassium, n-octyl potassium, phenyl sodium, ethyllithium, sec-butyl lithiym, t-butyl lithium and 2-ethylhexyl lithium.Sec-butyl lithium is the preferred initiator because it has a fastinitiation which is important in preparing polymers of narrow molecularweight distribution. It is preferred to employ the alkali metal salts oftertiary alcohols, such as potassium tbutyl alkoxylate, whenpolymerizing monomers having a nitrile or carbonyl functional group.

The alkali metal hydrocarbons and alkoxylates are either availablecommercially or may be prepared by known methods, such as by the,reaction of a halohydrocarbon, halobenzene or alcohol and theappropriate alkali metal.

An inert solvent generally is used to facilitate heat transfer andadequate mixing of initiator and monomer. Hydrocarbons and ethers arethe preferred solvents. Solvents useful in the anionic polymerizationprocess include the aromatic hydrocarbons such as benzene, toluene,xylene, ethylbenzene, t-butylbenzene, etc. Also suitable are thesaturated alphatic and cycloaliphatic hydrocarbons such as n-hexane,n-heptane, noctane, cyclohexane and the like. In addition, aliphatic andcyclic ether solvents can be used, for example, dimethyl ether, diethylether, dibutyl ether, tetrahydrofuran, dioxane, anisole,tetrahydropyran, diglyme, glyme, etc. The rates of polymerization arefaster in the ether solvents than in the hydrocarbon solvents, and smallamounts of ether in the hydrocarbon solvent increase the rates ofpolymerization.

The amount of initiator is an important factor in anionic polymerizationbecause it determines the molecular weight of the living polymer. If asmall proportion of initiator is used, with respect to the amount ofmonomer, the molecular weight of the living polymer will be larger thanif a large proportion of initiator is used. Generally, it is advisableto add initiator dropwise to the monomer (when that is the selectedorder of addition) until the persistence of the characteristic color ofthe organic anion, then add the calculated amount of initiator for themolecular weight desired. The preliminary dropwise addition serves todestroy contaminants and thus permits better control of thepolymerization. The monomer is then added as rapidly as possible, the

rate of addition being controlled by the ability of the system to removethe heat of polymerization and temperature control.

To prepare a polymer of narrow molecular weight distribution, it isgenerally preferred to introduce all of the reactive species into thesystem at the same time. By this technique, polymer growth byconsecutive addition of monomer takes place at the same rate to anactive terminal group, without chain transfer or termination reaction.When this is accomplished, the molecular weight of the polymer iscontrolled by the ratio of monomer to initiator, as seen from thefollowing representation:

Molecular Weight Of Living Polymer Moles of Monomer/Moles of Initiator XMolecular Weight Of Monomer As it can be seen from the above formula,high concentrations of initiator leads to the formation of low molecularweight polymers, whereas, low concentrations of initiator leads to theproduction of high molecular weight polymers.

The concentration of the monomer charged to the reaction vessel can varywidely, and is limited by the ability of the reaction equipment todissipate the heat of polymerization and to properly mix the resultingviscous solutions of the living polymer. Concentration of monomer ashigh as 50 percent by weight or higher based on the weight of thereaction mixture can be used. However, the preferred monomerconcentration is from about percent to about 25 percent in order toachieve adequate mixing.

As can be seen from the formula above and the foregoing limitations onthe concentration of the monomer, the initiator concentration iscritical, but may be varied according to the desired moleclar weight ofthe living polymer and the relative concentration of the monomer.Generally, the initiator concentration can range from about 0.001 toabout 0.1 mole of active alkali metal per mole of monomer, or higher.Preferably, the concentration of the initiator will be from about 0.01to about 0.004 mole of active alkali metal per mole of monomer.

The temperature of the polymerization will depend on the monomer.Generally, the reaction can be carried out at temperatures ranging fromabout -100C up to about 100C. When using aliphatic and hydrocarbondiluents, the preferred temperature range is from about C to about 100C.With ethers as the solvent, the preferred temperature range is fromabout -100C to about 100C. The polymerization of the styrene isgenerally carried out at slightly above room temperature; thepolymerization of alpha-methylstyrene preferably is carried out at lowertemperatures, e.g., 80C.

The preparation of the living polymer can be carried out by adding asolution of the alkali metal hydrocarbon initiator in an inert organicsolvent to a mixture of monomer and diluent at the desiredpolymerization temperature and allowing the mixture to stand with orwithout agitation until the polymerization is completed. An alternativeprocedure is to add monomer to a solution of the catalyst in the diluentat the desired polymerization temperature at the same rate that it isbeing polymerized. By either method the monomer is convertedquantitatively to a living polymer as long as the system remains free ofimpurities which inactivate the anionic species. As pointed out above,however, it is important to add all the reactive ingredients togetherrapidly to insure the formation of a uniform molecular weightdistribution of the polymer.

The anionic polymerization must be carried out under carefullycontrolled conditions, so as to exclude substances which destroy thecatalytic effect of the catalyst or initiator. For example, suchimpurities as water, oxygen, carbon monoxide, carbon dioxide, and thelike. Thus, the polymerizations are generally carried out in dryequipment, using anhydrous reactants, and under an inert gas atmosphere,such as nitrogen, helium. argon, methane, and the like.

The above-described living polymers are susceptible to further reactionsincluding further polymerization. Thus, if additional monomer, such asstyrene, is added to the living polymer, the polymerization is renewedand the chain grows until no more monomeric styrene remains.Alternatively, if another different anionically polymerizable monomer isadded, such as butadiene or ethylene oxide, the above-descried livingpolymer initiates the polymerization of the butadiene or ethylene oxideand the ultimate living polymer which results consists of a polystyrenesegment and a polybutadiene or polyoxethylene segment.

As noted above, the living polymers employed in the present inventionare characterized by relatively uniform molecular weight, i.e., thedistribution of molecular weights of the mixture of living polymersproduced is quite narrow. This is in marked contrast to the typicalpolymer, where the molecular weight distribution is quite broad. Thedifference in molecular weight distribution is particularly evident froman analysis of the gel. permeation chromatogram of commercial polystyene(Dow 666 u) prepared by free-radical polymerization and polystyreneproduced by the anionic polymerization process utilized in accordancewith the practice of the present invention.

PRODUCTION OF THE MACROMOLECULAR MONOMERS BY TERMINATION OF THE LIVINGPOLYMERS The living polymers herein are terminated by reaction with ahalogen-containing compound which also contains a polymerizable moiety,such as an olefinic group or an epoxy or thioepoxy group. Suitablehalogen-containing terminating agents include: the vinyl haloalkylethers wherein the alkyl groups contain six or fewer carbon atoms suchas methyl, ethyl, propyl, butyl, isobutyl, sec-butyl, amyl or hexyl;vinyl esters or haloalkanoic acids wherein the alkanoic acid containssix or fewer carbon atoms, such as acetic, propanoic, butyric,pentanoic, or hexanoic acid; olefinic halides having six or fewer carbonatoms such as vinyl halide, allyl halide, methallyl halide,6-halo-1-hexene, etc.; halides of dienes such as2-halomethyl-1,3-butadiene, epihalohydrins, acrylyl and methacrylylhalides, haloalkyl maleic anhydrides; haloalkylmaleate esters; vinylhaloalkylsilanes; vinyl haloaryls; and vinyl haloalkaryls, such asvinylbenzyl chloride (VBC); haloalkyl norbornenes, such as bromomethylnorbornene, bromonorbornane, and epoxy compounds such as ethylene orpropylene oxide. The halo group may be chloro, fluoro, bromo, or iodo;preferably, it is chloro. Anhydrides of compounds having an olefinicgroup or an epoxy or thioepoxy group may also be employed, such asmaleic anhydride, acrylic or methacrylic anhydride. The followingequations illustrate the typical termination reactions in accordancewith the practice of the present in vention:

Livia 2o]. r:

Terminating Agents:

(n) x- R SiRRC an In the above equations, R, R, R R and R are eachselected from the group consisting of hydrogen and lower alkyl, and arylradicals. Preferably, R will be lower alkyl, such as sec-butyl; R willbe either hydrogen or methyl; R will be phenyl; R will be hydrogen orlower alkylene radical; and R will be either hydrogen or lower alkylradical. The symbol n is a positive integer such that the properties ofthe polymer are manifest, i.e., a value such that the polymer will havea molecular weight in the range of from about 5.000 to about 50,000,preferably a molecular weight in the range of from about 10,000 to about35,000, more preferably a molecular weight in the range of from about12,000 to about 25,000.

Termination of the living polymer by any of the above types ofterminating agents is accomplished simply by adding the terminatingagent to the solution of living polymer at the temperature at which theliving polymer is prepared. Reaction is immediate and the solvents suchas tetrahydrofuran. It has been found that the hydrocarbon solvents suchas the aromatic hydrocarbons, saturated aliphatic and cycloaliphatichydrocarbons cause several differences in the reaction conditions andthe resulting product. For example, the termination reaction can beconducted at higher temperatures with hydrocarbon solvents as opposed tothe ether solvents. Also, the polar solvents such as tetrahydrofurantend to have a detrimental effect on the termi- 15 16 I nation reaction,particularly in the termination reaction As in the case of thetermination reaction, a slight of living polystyrene with allylchloride. molar excess of the capping reactant with respect to the lnsome instances, because of the nature of the living amount of initiatormay be used. The reaction occurs polymer and the monomer from which itis prepared, on a mole-for-mole basis.

or because of the nature of the terminating agent, cer- It will beunderstood that when a large molar excess tain deleterious sidereactions occur which result in an of alkylene oxide is reacted with theliving polymer, a impure product. For example, the carbanion of someliving polymer having two polymeric blocks is proliving polymers have atendency to react with funcduced. A typical example with polystyrenesegments tional groups or any active hydrogens of the terminatandpolyoxyalkylene segments is illustrated as follows: ing agent. Thus, forexample, acrylyl or methacrylyl l0 chloride while they act asterminating agents because of the presence of the chlorine atom in theirstructure. M cu ca ca cn(cu ca 0) CH cu 0 14 they also provide acarbonyl group in the terminated 2 2 2 x 2 2 polymer chain, and thiscarbonyl group may provide a I center for attackby a second highlyreactive living 15 polymer. The resulting polymer either has twice theexwherein x is a positive integer pected molecular weight or containssome chlorine, in- Either of the above described ethylene Oxide dicatingthat i f the living i i has been *"F capped polymers can be convenientlyterminated mated by reacilon wlth a second hvmg polymer or 2 with acompound containing a moiety reactive with the one of the activehydrocarbons of the acrylyl or metha- 0 anion of the capped polymer anda polymerizable end crylyl chlonde' group, including the followingtypical compounds: ac- It has been discovered that one means forovercomrylyl chloride, methacrylyl chloride, vinyl-2- ing the foregoingproblem is to render the reactive chloroethyl ether, vinylchloroacetate, chloromethylcarbanion less susceptible to reaction withthe funcmaleic anhydride and its esters, maleic anhydride tional groupsor any active hydrogens of a terminating (yields half ester of maleicacid following protonation agent. A preferred method to render theliving polymer with water), ally] and methallyl chloride andvinylbenless susceptible to the adverse reaction is to cap the zylchloride. highly reactive living polymer with a lesser reactive re- Thereaction of the above-described capped" living actant. Examples of somepreferred capping agents polymers with either acrylyl or methacrylylchloride include the lower alkylene oxides, i.e., one having eight canbe represented by the following reaction:

u CH2 C-C-Cl g. sec-Bu ca -cu (CH CH 0) --CH CH 0 L1 or fewer carbonatoms such as ethylene and propylene wherein n is a positive integer ofabout at least 50, .r is oxide; diphenyl ethylene, etc. The cappingreaction either 0 or a positive integer and R is either hydrogen yieldsa product which still is a living polymer, but or methyl.

yields puier Product .subsecuemiy relacted wlth When an epihalohydrin isused as the terminating ref i. z Agent comammg a uncnona group or agent,the resulting polymer contains a terminal epoxy do We y rogen group.This terminal epoxy may be used as the polylt has been found thatdiphenyl ethylene is an excellent capping agent" when terminating agentssuch as, for example, vinyl chloroalkanoates are employed.

A particularly preferred capping agent" is an alkylene oxide, such asethylene oxide. lt reacts with the living polymer, with the destructionof its oxirane ring. The following is a typical illustration of thecapping A5 one embodiment of the invention, the terminated reactionwhich shows the reaction of ethylene oxide polymer containing an epoxyor thioepoxy end group as a capping agent with a living polymer preparedby may be reacted with a polymcrizable carboxylic acid thepolymerization of styrene with sec-butyl lithium as halide, such asacrylic, methacrylic, or maleic acid halthe initiator: ide, to produce abeta-hydroxyalkyl acrylate, methamerizable group itself, such as in thepreparation of a poiyisobutylene or a polypropylene oxide backbone graftcopolymer or may be converted to various other useful polymerizable endgroups by any one of several known reactions.

The capping reaction is carried out quite simply, as crylate or maleateester as the polymerizable terminal in the case of the terminatingreaction, by adding the moiety of the substantially uniform molecularweight capping reactant to the living polymer at polymerizapolymer.These same polymerizable esters may be pretion temperatures. Thereaction occurs immediately. pared from the terminal epoxy polymer byfirst con- 17 verting the epoxy group to the corresponding glycol bywarming the polymer with aqueous sodium hydroxide, followed byconventional esterification of the glycol end group with the appropriatepolymerizable carboxylic acid, or acid halide.

The resulting glycol obtained by the aqueous hydro lysis of the epoxygroup in the presence of a base may be converted to a copolymer byreaction with a high molecular weight dicarboxylic acid which may beprepared, e.g., by the polymerization of a glycol or diamine with amolar excess of phthalic anhydride, maleic anhydride, succinicanhydride, or the like. These reactions can be modified to obtain apolystyrene block and a polyamide block (Nylon). The glycol terminatedpolymer may also be reacted with a diisocyanate to form a polyurethane.The diisocyanate may be, e.g., the reaction product of a polyethyleneglycol having an average molecular weight of 400 with a molar excess ofphenylene diisocyanate.

In another embodiment of the invention, an organic epoxide iscopolymerized with a terminated polymer containing an epoxy or thioepoxyend group. The graft copolymer which results is characterized by abackbone uninterrupted segments of at least about 20, and preferably atleast about 30, recurring units of the organic epoxide. Preferredorganic epoxides include ethylene oxide, propylene oxide, butyleneoxide, hexylene oxide, cyclohexene epoxide and styrene oxide, i.e..those having 8 or fewer carbon atoms.

When a haloalkylmaleic anhydride or haloalkylrnaleate ester is used asthe terminating agent. the resulting terminal groups can be converted byhydrolysis to carboxyl groups. The resulting dicarboxylic polymer may becopolymerized with glycols or diamines to form polyesters and polyamideshaving a graft copolymer structure.

If it is desired to isolate and further purify the macro molecularmonomer from the solvent from which it was prepared, any of the knowntechniques used by those skilled in the art in recovering polymericmaterials may be used. These techniques include: (1) solvent-nonsolventprecipitation; (2) evaporation of solvent in an aqueous media; and (3)evaporation of solvent, such as by vacuum roll drying, spray drying,freezing drying; and (4) steam jet coagulation.

The isolation and recovery of the macromolecular monomer is not acritical feature of the invention. In fact. the macromolecular monomerneed not be recovered at all. Stated otherwise, the macromolecularmonomer, once formed, can be charged with the suitable monomer andpolymerization catalyst to conduct the graft copolymerization in thesame system as the macromolecular monomer was prepared, providing thesolvent and materials in the macromolecular monomer preparation reactordo not poison the catalyst or act in a deleterious manner to the graftcopolymerization process. Thus, ajudicious selection of the solvent andpurification of the reactor system in the preparation of themacromolecular monomer can ultimately result in a large savings in theproduction of the graft copolymers of the present invention.

As pointed out above, the macromolecular monomers, which ultimatelybecome the sidechains of the graft copolymers by being integrallypolymerized into the backbone polymer, must have a narrow molecularweight distribution. Methods for determining the molecular weightdistribution of polymers such as the macromolecular monomers are knownin the art. Using these known methods, the weight average molecularweight (Mw) and the number average molecular weight (Mn) can beascertained, and the molecular weight distribution (MW/Mn) for themacromolecular monomer can be determined. The macromolecular monomersmust have nearly a Poisson molecular weight distribution or be virtuallymonodispense in order to have the highest degree of functionality. Preferably, the ratio of Mw/Mn of the novel macromolecular monomers will beless than about H. The macromolecular monomers of the present inventionpossess the aforementioned narrow molecular Weight distribution andpurity due to the method of their preparation, described hereinabove.Thus, it is important that the sequence of steps in preparing themacromolecular monomers be adhered to in order to produce the optimumresults in beneficial properties in the graft copolymers.

GRAFT COPOLYMERIZATION Prior to the invention hereinjgraft copolymerswere prepared by synthesizing a linear backbone, then grafting onto thisbackbone, growing polymeric or preformed polymeric chains. These methodsgenerally require elaborate equipment and produce a mixture of productshaving inferior properties unless further purified. Because of theadditional processing conditions and the use of special equipment, theseprocesses are not economically feasible.

Although some of the prior art graft copolymers, such as those describedin U.S. Pat. Nos. 3,627,837, 3,634,548 and 3,644,584 and British Pat.Nos. 873,656 and 1,144,151 resemble the graft copolymers of the presentinvention. Generally, the present graft copoly' mers are differentcompositions, not only because they are prepared by significantlydifferent processes. but because the pendant polymeric chains of thegraft copolymers of this invention are of relatively uniform, minimumlength, and are each an integral part of the backbone. Furthermore, thebackbone of the graft copolymers of the present invention containpolymeric segments of certain minimum length. Thus, the present graftcopolymers differ structurally because the macromolecular monomer isinterposed between polymeric segments of the backbone polymer, ratherthan being merely attached to the backbone polymer in a random manner.These characteristics contribute materially to the advantageousproperties which inhere in these novel graft copolymers.

The graft copolymers of the present invention are prepared by firstsynthesizing the pendant polymeric chains (the polymerizable terminatedliving polymers) then copolymerizing the terminal portions of thepolymeric chains with the second monomer during the formation of thebackbone polymer.

In accordance with the practice of the present invention, thesubstantially pure macromolecular monomers of high controlled molecularweight and molecular weight distribution have an appropriate reactiveend group suitable for any mechanism of copolymerization, e.g.,free-radical, cationic, anionic, Ziegler catalysis, and condensation.Thus, the reactive end group is selected for easy copolymerization withlow cost monomers by conventional means and within existingpolymerization equipment.

The copolymerization with the macromolecular monomers and the secondreactive monomer is a graftlike structure where the pendant chain is apolymer whose molecular weight and distribution are predetermined byindependent synthesis. The distribution of the side-chain polymer alongthe backbone is controlled by the reactivity ratios of the comonomers.The additional cost of the graft copolymers is minimal, since very fewmoles, on a molar basis, of the macromolecular monomer are used ascompared to the second low cost conventional monomer.

Since the reactive end group of the macromolecular monomer iscopolymerized with the second monomer, it is an integral part of thebackbone polymer. Thus, the polymerizable end group of themacromolecular monomer is interposed between large segments of thebackbone polymer.

The present invention provides a means for controlling the structure ofthe graft copolymer. More specifically, the control of the structure ofthe graft copolymer can be accomplished by any one or all of thefollowing means: (1 by determining the reactivity ratio of themacromolecular monomer and a second monomer during the copolymerizationreaction, a pure graft polymer free from contamination by homopolymerscan be prepared; (2) by controlling the monomer addition rates duringthe copolymerization of a macromolecular monomer and a second monomer.the distance between the sidechains in the polymer structure can becontrolled; and (3) the size of the graft chain can be predetermined andcontrolled in the anionic polymerization step of the preparation of themacromolecular monomer.

It will be apparent to those skilled in the art that by the properselection of terminating agents, all mechanisms of copolymerization maybe employed in preparing the controlled phase separated graftcopolymers.

As alluded to hereinabove, the chemically joined, phase separated graftcopolymers of the present invention are preferably copolymerized withany ethylenically unsaturated monomer including the vinylidene typecompounds containing at least one vinylidene CH C- group and preferablythe vinyl-type compounds containing the characteristic CH ==CH- groupwherein hydrogen is attached to one of the free valences of thevinylidene group. The copolymerization, as pointed out above, is onlydependent upon the relative reactivity ratios of the terminal group andthe comonomer.

Examples of some of the preferred ethylenicallyunsaturated compoundsused as the comonomers include the acrylic acids, their esters, amidesand nitriles including acrylic acid, methacrylic acid, the alkyl estersof acrylic and methacrylic acid, acrylonitrile, methacrylonitrile,acrylamide, methacrylamide, N,N,- dimethacrylamide (NNDMA); the vinylhalides such as vinyl chloride, and vinylidene chloride; the vinylcyanides such as vinylidene cyanide (1,1- dicyanoethylene); the vinylesters of the fatty acids such as vinyl acetate, vinyl propionate andvinyl chloroacetate, etc.; and the vinylidene containing 'dicarboxylicanhydrides. acids and esters, such as fumaric acid and esters, maleicanhydrides, acids, and esters thereof A particularly important class ofvinylidene type compounds useful as comonomers with the alphaolefin andstyrene terminated macromolecular mono- LII mers include the vinylolefinic hydrocarbons, such as ethylene, propylene, l-butene,isobutylene, l-pentene, l-hexene, styrene. 3-methyl-l-butene,4-methyl-lhexene and cyclohexcne. Also. there may be used as thecomonomers the polyolefinic materials containing at least one vinylidenegroup such as the butadienel ,3 hydrocarbons including butadiene,isoprene, piperylene and other conjugated dienes. well as otherconjugated and non-conjugated polyolefinic monomers including divinylbenzene, the diacrylate type esters of methylene, ethylene. polyethyleneglycols, and polyallyl sucrose.

The most preferred cthylenically unsaturated comonomers are thecommercially available and widely used monomers such as methyl acrylate,butyl acrylate, 2- ethyl hexyl acrylate, methyl methacrylate, vinylchloride, vinylidene chloride, vinylidene cyanide. acrylonitrile; andthe hydrocarbon monomers such as ethylene, propylene, styrene; and theconjugated dienes such as butadiene and isoprene.

In addition to the hereinabove described ethyleni cally unsaturatedcomonomers useful in the practice of the invention. there are includedthe comonomers capable of copolymerizing by condensation or stepreactionpolymerization conditions with the polymerizable macromolecular monomersof the invention. in this connection, the polymerizable macromolecularmonomers will contain the appropriate terminal groups necessary tofacilitate the condensation reaction. For example, living polymersterminated with epichlorohydrin will contain an epoxy terminal groupwhich converts to a m m a-CH-Cll group upon sponification. This vicinalhydroxy group is capable of copolymerizing with polybasic acids andanhydrides to form polyesters, such as adipic acid, phthalic anhydride,maleic anhydride, succinic anhydride, trimellitic anhydride, etc.;aldehydes to form polyacetals, such as polyformaldehyde.ureaformaldehydes, acetaldehydes, etc.; polyisocyanates andpolyisocyanateprepolymers to form polyurethanes; and siloxanes to formpolysiloxanes. The living polymersterminated with halomaleic anhydrideor halomaleate ester may be converted to terminal carboxyl groups byconventional hydrolysis. The resulting dicarboxylic terminated polymercan be copolymerized with glycols to form polyesters or with diamines toform polyamides having a graft copolymer structure. Alternatively. themaleic anhydride or ester terminal group or the polymer can be used inthe condensation polymerization S with the glycols or diamines. Thevicinal hydroxy or 1 bone is dependent on the terminal group of themacromolecular monomer and the reactivity of the comonomer.

The macromolecular monomers of the invention are stable in storage anddo not significantly homopolymerize. Furthermore, the macromolecularmonomer copolymerizes through the terminal double bond or reactive endgroup and is not incorporated into the polymeric backbone by graftingreactions to the polymer of the (1) (1M1 H1 r 141/14 1 simply reduces tothe approximation:

( l/ v r/"z M2 when M. is in very low molar concentrations. Thus. themacromolecular monomer (M copolymerization with other monomers (M aredescribed only by r values and monomer feed compositions. Rearrangementof equation (2) gives:

(3) r dMg/Mg/dM /IT "/r Conversion M- Conversion M.

The reactivity ratio. r can be estimated from a relatively lowconversion sample of a single copolymerization experiment. The validityof this concept of a predictable and controllable reactivity of themacromolecular monomer can thereby be established. It has been shownthat the reactivity of commercial monomers with the macromolecularmonomers of the present invention with various end groups correlate withavailable literature values for reactivity ratios of r- The method ofthe present invention permits the utilization of all types ofpolymerizable monomers for incorporation into backbone polymers. andmakes it possible for the first time to design and build graftcopolymers of controlled molecular structure, and of backbone and graftsegments with different properties, such as hydrophobic and hydrophilicsegments. crystalline and amorphous segments, polar and non-polarsegments. segments with widely different glass transition temperatures.whereas prior work on SDS terblock copolymers had been limited to theincompatibility of glassy polystyrene blocks with rubbery polydieneblocks.

The copolymerization of the polymerizable macromolecular monomers withthe comonomers may be conducted in a wide range of proportions.Generally speaking. a sufficient amount of the macromolecular monomershould be present to provide the chemically joining of at least one ofthe uniform molecular weight sidechain polymers to each backbonepolymer. so that a noticeable effect on the properties of the graftcopolymeric properties can be obtained. Since the molecular weight ofthepolymerizable macromolecular monomer generally exceeds that of thepolymerizable comonomers. a relatively small amount of the polymerizablemacromolecular monomer can be employed. However, the chemically joined.phase separated thermoplastic graft copolymers may be prepared bycopolymerizing a mixture containing up to about 95 percent by weight. ormore. of the polymerizable macromolecular monomers of this invention,although mixtures containing up to about 60 percent by weight of thepolymerizable macromolecular monomer are preferred. Stated other- LIIwise. the resinous thermoplastic chemically joined. phase separatedgraft copolymer of the invention is comprised of I) from 1 percent toabout percent by weight of the polymerizable macromolecular monomerhaving a narrow molecular weight distribution (i.e., a Mw/Mn ofless thanabout 1.1), and (2) from 99 percent to about 5 percent by weight of acopolymerizable comonomer defined hereinabove.

The polymerizable macromolecular monomers copolymerize with thehereinabove referred to comonomers in bulk. in solution. in aqueoussuspension and in aqueous emulsion systems suitable for the particularpolymerizable macromolecular monomer. its end group and the copolymeremployed. If a catalyst is emloyed. the polymerization environmentsuitable for the catalyst should be employed. For example. oilorsolventsoluble peroxides such as benzoyl peroxides, are generallyeffective when the polymerizable macromolecular monomer is copolymerizedwith an ethylenically unsaturated comonomer in bulk. in solution in anorganic solvent such as benzene. cyclohexane. hexane. toluene. xylene.etc.. or in aqueous suspension. Water-soluble peroxides such as sodium.potassium, lithium and ammonium persulfates. etc, are useful in aqueoussuspension and emulsion systems. In the copolymerization of many ofthepolymerizable macromolecular monomers, such as those with anethylenically unsaturated end group and a polystyrene. polyisoprene orpolybutadiene repeating unit. an emulsifier or dispersing agent may beemployed in aqueous suspension systems. In these systems, particularadvantage can be achieved by dissolving the water-insolublepolymerizable macromolecular monomer in a small amount of a suitablesolvent. such as a hydrocarbon. By this novel technique, the comonomercopolymerizes with the polymerizable macromolecular monomer in thesolvent. in an aqueous system surrounding the solvent-polymer system. Ofcourse. the polymerization catalyst is chosen such that it will besoluble in the organic phase of the polymerization system.

As previously stated. various different catalyst systems can be employedin the present invention for the copolymerization process. It will beapparent to those skilled in the art that the particular catalyst systemused in the copolymerization will vary. depending on the monomer feedand the particular end group on the macromolecular monomer. For example,when using a macromolecular monomer having a vinyl acetate end group.best results are generally obtained by employing free-radical catalystsystems. On the other hand. copolymerization utilizing isobutylenemonomer feed with either an allyl. methallyl or epoxy terminatedmacromolecular monomer, best results are accomplished by utilizing thecationic polymerization techniques. Since the particular polymerizableend group on the macromolecular monomer will depend on the comonomerfeed employed because of the relative reactivity ratios, thepolymerization mechanism commonly employed for the particular comonomerwill be used. For example, ethylene polymerizes under free-radical,cationic and coordination polymerization conditions; propylene andhigher alpha-olefins only polymerize under coordination polymerizationconditions. isobutylene only polymerizes under cationic polymerizationconditions; the dienes polymerize by free-radical, anionic andcoordination polymerization conditions; styrene polymerizes underfree-radical, cationic, anionic and coordination conditions, vinylchloride polyinerizes under freeradical and coordination polymerizationconditions; vinylidene chloride polymerizes under free-radical andanionic polymerization conditions; vinyl fluoride polymerizes underfree-radical conditions: tetrafluor oethylene polymerizes underfree-radical and coordi nation polymerization conditions; vinyl etherspolymerize under cationic and coordination polymerization conditions;vinyl esters polymerize under free-radical polymerization conditions;acrylic and methacrylic esters polymerize under free-radical. anionicand coordination polymerization conditions; and acrylonitrilepolymerizes under free-radical. anionic and coordination polymerizationconditions.

It will be understood by those skilled in the art that the solvent.reaction conditions and feed rate will be partially dependent upon thetype of catalyst system utilized in the copolymerization process. One ofthe considerations. of course. will be that the macromolecular monomerbe dissolved in the solvent system utilized. It is not necessary,however. for the monomer feed to be soluble in the solvent system.Generally. under these conditions during the formation of the copolymer.the graft copolymer will precipitate out of the solvent wherein it canbe recovered by techniques known in the polymerart.

The temperature and pressure conditions during the copolymerizationprocess will vary according to the type of catalyst system utilized.Thus. in the production of low density polyolefin backbones underfree-radical conditions. extremely high pressures will be employed. Onthe other hand. the high density substantially linear polyolefinbackbone polymers produced by the coordination type catalyst generallywill be prepared under moderately low pressures.

When preparing graft copolymers having a polyolefin backbone of ethyleneor propylene or copolymers of .ethylene and propylene together with amacromolecular monomer. it is preferred to employ a coordinationcatalyst known in the art as the Ziegler catalyst and Natta catalysts(the latter being commonly used for polypropylene). That is. materialsadvanced by Professor-Dr. Karl Ziegler of the Max Plenck lnstitute ofMulheim. Ruhr. Germany. and Dr. Giulio Natta of Milan. ltaly. Some ofthese catalysts are disclosed in Belgian Pat. No. 533.362. issued May16. 1955. and U.S. Pat. Nos. 3.113.115 and 3.257.332 to Ziegler et al.These catalysts are prepared by the interaction of a compound oftransition metals of group lV-Vlll in the periodic table. the catalyst.and an organometallic compound derived from group l-lll metals. asco-catalyst. The latter are compounds such as metal hydrides and alkylscapable of giving rise to hydride ions or carbanions. such as trialkylaluminum. Compounds of the transition elements have a structure withincomplete d-shells and in the lower valence states. can associate withthe metal alkyls to form complexes with highly polarized bonds. Thoseelements hereinabove referred to as the catalysts are preferablytitanium. chromium. vanadium. and zirconium. They yield the best Zieglercatalysts by reaction of their compounds with metal alkyls.

As previously stated. the solvent system utilized will most convenientlybe the solvent employed in the preparation of the macromolecularmonomer. Solvents useful for the polystyrene macromolecular monomers arethose which dissolve polystyrene. Typical solvents for .24 polystyreneinclude cyclohexane. benzene. toluene. xylene. decalin. tetralin. etc.

The copolymerization reaction may be conducted at any suitabletemperature. depending on the particular catalyst. macromolecularmonomer. monomer feed. resulting graft copolymer and solvent used.Generally.

the graft copolymerization will be conducted at a temperature of fromabout 10C to about 500C. preferably from about 20c to about l(.)()C.

The graft copolymerization reaction is preferably conducted by placing apredetermined amount of the macromolecular monomer dissolved in theappropriate solvent in the reactor. The polymerization catalyst andmonomer are thereafter fed into the solvent system to produce the graftcopolymer.

It is generally desirable to provide a graft copolymer having at leastabout 2 percent macromolecular monomer incorporated in the backbonepolymeric material. however. satisfactory results can be obtained withup to about 40 percent by weight macromolecular monomer incorporation.Preferably. the graft copolymers of the present invention will haveabout 5 percent to about 20 percent by weight incorporation of themacromolecular monomer into the backbone polymeric material to obtainthe optimum physical properties of both the sidechain polymer and thebackbone polymer. However. graft copolymers having up to about 95percent by weight of the macromolecular monomers incorporated thereinmay be prepared and are contemplated within the scope of the invention.

The means for providing the proper amount of inc0rporation of themacromolecular monomer can be determined simply by adding theappropriate weight macromolecular monomer used in the copolymerizationprocess. For example. if a graft copolymer having 10 percent by weightincorporation of the macromolecular monomer into the backbone polymer isdesired. one simply employs 10 parts by weight of the macromolecularmonomer for each parts by weight of the monomer feed.

Following the procedures outlined above. graft copolymers having uniquecombinations of properties are produced. These unique combinationsofproperties are made possible by the novel process herein which forcesthe compatibility of otherwise incompatible polymeric segments. Theseincompatible segments segregate into phases of their own kind.

The chemically joined. phase separated graft copolymers of the inventionmicroscopically possess a controlled dispersion of the macromolecularsidechain in one phase (domain) within the backbone polymer phase(matrix). Because all of the macromolecular monomer sidechain domainsare an integral part or interposed between large segments of thebackbone polymer. the resulting graft copolymer will have the propertiesof a cross-linked polymer. if there is a large difference in the Tg orTm of the backbone and sidechain segments. This is true only up to thetemperature required to break the thermodynamic cross-link of the Idispersed phase. In essence. a physically cross-linked (as opposed tochemical cross-linked) type polymer can be made that is reprocessibleand whose properties are established by simple cooling. rather thanvulcanization or chemical cross-linking.

The graft copolymers of the present invention are differentiated fromthe macroscropic opaque and weak blends of incompatible polymers of theprior art. The graft copolymers of this invention contain separatephases which are chemically joined and the dispersion of one segmentinto the matrix polymer is on a microscopic level and below thewavelength of light of the matrix polymer. The graft copolymers hereinare, therefore, transparent, tough, and truly thermoplastic.

An illustrative example of the present invention includes combining theadvantageous properties of polystyrene with the advantageous propertiesof polyethylene, although these two polymers normally are incompatiblewith one another and a mere physical mixture of these polymers has verylittle strength and is not useful. To combine these advantageousproperties in one product, it is necessary that the different polymericsegments be present as relatively large segments. The properties ofpolystyrene do not become apparent until the polymer consistsessentially of at least about 20 recurring monomeric units. This samerelationship applies to the polymeric segments present in the graftcopolymers herein, i.e., if a graft copolymer comprising polystyrenesegments is to be characterized by the advantageous properties ofpolystyrene. then those poly-- styrene segments must, individually.consist essentially of at least about 20 recurring monomeric units. Thisrelationship between the physical properties of a polymeric segment inits minimum size is applicable to the polymeric segment of all graftcopolymers herein. In general, the minimum size of a polymeric segmentwhich is associated with the appearance of the physical properties ofthat polymer in the graft copolymers herein is that which consists ofabout 20 recurring monomeric units. Preferably, as noted earlier herein,the polymeric segments both of the copolymeric backbone and thesidechains, will consist essentially of more than about recurringmonomeric units. However, as it is well-known, the highly beneficialproperties of polymers such as polystyrene are generally apparent whenthe polymer has a molecular weight of from about 5,000 to about 50,000,preferably from about 10,000 to about 35,000, more preferably 12,000 toabout 25.000.

The polymeric segments of the graft copolymers of the invention maythemselves be homopolymeric or they may be copolymeric. Thus, a graftcopolymer of this invention may be prepared by the copolymerization ofethylene, propylene, and a terminated polystyrene containing apolymerizable alpha-olefin end group. The uninterrupted polymericsegments of the backbone of such a graft copolymer will be copolymersegments of ethylene and propylene.

The graft copolymers comprising polymeric segments having fewer thanabout 20 recurring monomeric units are, nevertheless, useful for manyapplications, but the preferred graft copolymers are those in which thevarious polymeric segments have at least about 20 recurring monomericunits.

Although, as indicated, the graft copolymers herein are characterized bya wide variety of physical properties, depending on the particularmonomers used in their preparation, and also on the molecular weights ofthe various polymer segments within a particular graft copolymer, all ofthese graft copolymers are useful as tough, flexible, self-supportingfilms. These films may be used as food-wrapping material, paintersdropcloths, protective wrapping for merchandise displayed for sale, andthe like.

Graft copolymers of the macromolecular monomer,

' polystyrene, with ethylene-propylene, isobutylene, or

propylene oxide monomers have been found to be stable materials thatbehave like vulcanized rubbers, but are thermoplastic and reprocessable.Thus, an extremely tough, rubbery plastic is obtained without theinherent disadvantages of a vulcanized rubber. These copolymerizedrubber-forming monomers with the macromolecular monomers of the presentinvention have the additional use as an alloying agent for dispersingadditional rubber for impact plastics.

Just as metal properties are improved by alloying, so are polymerproperties. By adding the appropriate amount of an incompatible materialto a plastic in a microdispersed phase, over-all polymer properties areimproved. A small amount of incompatible polybutadiene rubber correctlydispersed in polystyrene gives high impact polystyrene. The key to thismicrodispersion is a small amount of chemical graft copolymer that actsas a flux for incorporating the incompatible rubber.

[n a similar manner, a copolymer of the macromolecular monomer of thepresent invention can be the flux for incorporating or dispersingincompatible polymers into new matrices making possible a whole new lineof alloys, impact plastics, malleable plastics, and easy-toprocessplastics.

The use of the graft copolymers are alloying agents is particularlyexemplified in the .case of polyethylenepolystyrene blends. As it iswell-known, polyethylene and polystyrene are incompatible when blendedtogether. However, when using the graft copolymers of the presentinvention as an alloying agent, the polyethylene and polystyrene phasescan be conveniently joined.

For example, a blend prepared by mixing to 51 parts by weight ofcommercial polyethylene (either low or high density) 10 to 49 parts byweight of commercial polystyrene and 5 to 30 parts by weight of a graftcopolymer of the present invention comprising polystyrene sidechains anda polyethylene backbone are useful in making automobile parts, such asinner door panels, kick panels, and bucket seat backs, or applianceparts such as television components. Such blends are also useful asstructural foams, sheets and films, containers and lids in packaging,beverage cases, pails, in the manufacture of toys, molded sheets infurniture, hot mold adhesives and computer and magnetic tapes.

The use of the graft copolymers of the present invention as an alloyingagent offers a distinct advantages over the prior art blends, inasmuchas the plastic blend can be processed with'minimized phase separation ofthe polystyrene and polyethylene polymers in the blend. The strength ofthe novel blends of the present invention is also improved over theblends of the prior art.

lfthe polystyrene in the macromolecular monomer is replaced by apoly(alpha-methylstyrene) and is copolymerized with ethylene, a similarpolyblend can be prepared as described above. However, these blends willhave heat stability which will allow the resulting plastics to be usefulin making hot water pipes, sheets in warm areas, and automobile parts,having oxidative stability over rubber-containing materials. Theseplastics also have utility in preparing reinforced fiberglass andfillers due to their good adhesion to fiberglass. Polyblends ofpoly(alphamethylstyrene) graft copolymer with large amounts, i.e., 51-90percent by weight of (poly(alpha-methylstyrene) and -49 percentpolyethylene. exhibit a higher heat distortion, together with highimpact strength and high modulus. These plastics are useful in variousengineering applications and in the manufacture of parts of aircraft,auto bodies, recreational vehicles, appliances, gears, bearings, etc.

Another useful blend utilizing the graft copolymers of the presentinvention comprises mixing 10 to 49 parts of low density polyethylene,51 to 91 parts by weight of (alpha-methylstyrene) and zero to 30 partsby weight of polystyrene and 5 to 30 parts by weight of the graftcopolymer of the present invention comprising polyethylene backbone withpoly(alpha-methylpolystyrene) or styrene sidechains. The blend isextruded in a mill and the resultant plastic is found useful in makingappliances such as coffee makers, humidifiers, high intensity lamps,color television sets, kitchen-range hardware, blenders, mixers, andelectric toothbrushes. These plastics are also useful in preparingrecreational vehicles such as snowmobile parts and helmets; machineparts such as gears, bearings. plumbing parts such as shower heads,valves, fittings and ballcocks; and motor housing, stamping. lawnsprinklers, stereo tape or cartridges, etc.

The reinforcement of plastics by adding glass fibers or other materialsis difficult to achieve because of poor wetting character of many basicpolymers. The macromolecular monomers of the present invention,particularly those containing reactive polystyrene, have a tendency towet and bond to glass with facility. By proper dispersion of glass in amacromolecular copolymer, it is possible to upgrade the bond between thedispersed phase and glass. Thus, the macromolecular graft copolymers ofthe present invention can also be used as reinforcing adhesion aids toglass fibers.

The invention is illustrated further by the following examples which,however, are not to be taken as limiting in any respect. In each case,all materials should be pure and care should be taken to keep thereacted mixtures dry and free of contaminants. All parts andpercentages, unless expressly stated to be otherwise, are by weight.

Preparation Of Macromolecular Monomer Sidechains Having UniformsMolecular Weight EXAMPLE 1 (a) Preparation Of Polystyrene Terminatedwith Allyl Chloride:

A stainless steel reactor is charged with 76.56 parts of A.C.S. gradebenzene (thiophene-free), which had been pre-dried by Linde molecularsieves and calcium hydride. The reactor is heated to C and 0.015 partsof diphenylethylene is added to the reactor by means of a hypodermicsyringe. A 12.1 percent solution of sec-butyl lithium in hexane is addedto the reactor portionwise until the retention of a permanent orangeyellow color, at which point an additional 0.885 parts 1.67 moles) ofsec-butyl lithium solution is added, followed by the addition of 22.7parts (218 moles) of styrene over a period of 44 minutes. The reactortemperature is maintained at 36-42C. The living polystyrene isterminated by the addition of 0.127 parts of allyl chloride to thereaction mixture. The resulting polymer is precipitated by the additionof the alpha-olefin terminated polystyrenebenzene solution intomethanol, whereupon the polymer precipitates out of solution. Thealpha-olefin terminated polystyrene is dried in an air circulatingatmosphere drier at 4050C and then in a fluidized bed to remove thetrace amounts of methanol. The methanol content after purification is 10parts per million. The molecular weight of the polymer, as determined bymembrane phase osmometry, is 15,400 (theory: 13,400) and the molecularweight distribution is very narrow, i.e., the Mw/Mn is less than 1.05.The macromolecular monomer has the following structural formula:

CH C11 611 I Cl! 2 (CR C11 4511 an an on n z 2 EXAMPLE 2 a PreparationOf Poly(alpha-methylstyrene) Terminated With Allyl Chloride:

A solution of 472 grams (4.0 moles) of alphamethylstyrene in 2500 ml. oftetrahydrofuran is treated dropwise with a 12 percent solution ofn-butyl lithium in hexane until the persistence of a light red color. Anadditional 30 ml (0.0383 mole) of this n-butyl lithium solution isadded, resulting in the development of a bright red color. Thetemperature of the mixture is then lowered to -C, and after 30 minutesat this temperature, 4.5 grams (0.06 mole) of allyl chloride is added.The red color disappears almost immediately, indicating termination ofthe living polymer. The resulting colorless solution is poured intomethanol to precipitate the alpha-olefin terminatedpoly(alpha-methylstyrene) which is shown by vapor phase osmometry tohave a number average molecular weight of 11,000 (theory: 12,300) andthe molecular weight distribution is very narrow, i.e., the Ms/Mn isless than 1.05. The macromolecular monomer produced has the followingstructural formula:

ca CH ca en ug-t --CH CH CH following structural formula:

c. methacrylonitrile, terminating with a molar equivalent of vinlbenzylchloride to produce a polymer having the following structural formula:

d. methyl methacrylate, terminating with vinylbenzyl chloride to producea polymer having the following structural formula:

ca -Gen ca e. N,N-dimethylacrylamide, terminating with pvinylbenzylchloride to produce a polymer having the following structural formula:

EXAMPLE 3 Preparation Of Polystyrene Terminated With Vinyl ChloroacetateA solution of one drop of diphenyl ethylene in 2500 ml. of cyclohexaneat 40C is treated portionwise with a 12 percent solution of secbytyllithium in cyclohexane until the persistence of a light red color, atwhich point an additional 18 ml. (0.024 mole) of the sec-butyl lithiumis added, followed by 312 grams (3.0 moles) of styrene. The temperatureof the polymerization mixture is maintained at 40C for 30 minutes,whereupon the living polystyrene is capped by treatment with 8 ml.(0.040 mole) of diphenyl ethylene, then terminated by treatment with 6ml. (0.05 mole) of vinyl chloroacetate. The resulting polymer isprecipitated by addition of the cyclohexane solution to methanol and thepolymer is separated by filtration. lts number average molecular weight,as determined by vapor phase osmometry, is 12,000 (theory: 13,265), andthe molecular weight distribution is very narrow, i.e., the Mw/Mn isless than 1.06. The macromolecular monomer produced has the followingstructural formula:

[3 o r 1| ca ca mn m cu cu cn c -cn cocn c11 wherein n has a value suchthat the molecular weight of the polymer is 12,000.

EXAMPLE 4 Preparation Of Poly(alpha-methylstyrene) Terminated With VinylChloroacetate of a bright red color. The temperature of the mixture isthen lowered to 80C, and after 30 minutes at that temperature, 5.6 ml.of diphenyl ethylene is added. The

0 resulting mixture is poured into 5.0 ml. (0.04 mole) of vinylchloroacetate and the thus terminated poly(alpha-methylstyrene) isprecipitated with methanol and separated by filtration. lts numberaverage molecular weight, as determined by vapor phase osmometry, is14,280 (theory: 12,065) and the molecular weight distribution is verynarrow. The macromolecformula:

wherein n has a value such that the molecular weight of the polymer is14,280.

EXAMPLE 5 Preparation of Polystyrene Terminated with Vinyl-2ChloroethylEther A solution of one drop of diphenyl ethylene at 40C is treatedportionwise with a 12 percent solution of tbutyl lithium in pentaneuntil the persistence of a light red color, at which point an additional30 ml. (0.84 mole) of the t-butyl lithium solution is added, followed by312 grams (3.0 moles) of styrene. The temperature of the polymerizationmixture is maintained at 40C for 30 minutes, whereupon the livingpolystyrene is terminated by treatment with 8 ml. (0.08 mole) ofvinyl-2- chloroethyl ether. The resulting polymer is precipitated byaddition of the benzene solution to methanol and the polymer isseparated by filtration. lts number average molecular weight, asdetermined by vapor phase osmometry, is 7,200 (theory: 7,870) and themolecular weight distribution is very narrow, i.e., the Mw/Mn is lessthan 1.06. The macromolecular monomer produced has the followingstructural formula:

Preparation Of Polystyrene Terminated With Epichlorohydrin A benzenesolution of living polystyrene is prepared in Example 5 and terminatedby treatment with 10 grams (0.10 mole) of epichlorohydrin. The resultingterminated polystyrene is precipitated with methanol and separated byfiltration. lts molecular weight, as shown by vapor phase osmometry, is8,600 (theory: 7,757) and its number average molecular weightdistribution is very narrow. The macro-molecular monomer produced hasthe following structural formula:

wherein n has a value such that the molecular weight of the polymer is8,660.

EXAMPLE 7 (a) Preparation Of Polystyrene Terminated With MethacrylylChloride:

To a solution of 0.2 ml. of diphenyl ethylene in 2,500 ml. of benzenethere is added dropwise a 12 percent solution of n-butyl lithium inhexane until the persistence of a light reddish-brown color. Anadditional 24 ml. (0.031 mole) of this n-butyl lithium solution isadded, and then. 416 grams (4.0 moles) of styrene, resulting in thedevelopment of an orange color. A temperature of 40C is maintainedthroughout by external cooling and by controlling the rate at which thestyrene is added. This temperature is maintained for an additional 30minutes after all of the styrene has been added, and then is lowered to20C, whereupon 4.4 grams (0.1 mole) of ethylene oxide is added, causingthe solution to become colorless. The living polymer is terminated byreaction with 10 ml. (0.1 mole) of methacrylyl chloride. The resultingpolymer has a number average molecular weight as shown by vapor phaseosmometry of 10,000. The macromolecular monomer has the followingstructural formula:

0 ca cu cu ca Lcn ll CH CH OC? I CH L n C1 wherein n has a value suchthat the molecular weight of the polymer is 10,000.

b. Acrylyl chloride is substituted for methacrylyl chloride in the aboveprocedure to give an acrylic acid ester end group on the polystyrenechain.

c. Allyl chloride is substituted for methacrylyl chloride in procedure(a) to produce an ally] ether terminated polystyrene.

d. Methallyl chloride is substituted for methacrylyl chloride inprocedure (a) to produce methallyl ether terminated polystyrene.

e. Maleic anhydride is substituted for methacrylyl chloride in procedure(a), followed by protonation with water to produce polystyreneterminated with the half ester of maleic acid.

f. Epichlorohydrin is substituted for methacrylyl chloride to produceanepoxy ether terminated polystyrene.

g. The procedure of (a) is repeated using in place of styrene, anequivalent amount of isoprene and in place of n-butyl lithium anequivalent amount of sec-butyl lithium to produce primarily a rubberycis-l,4-

lowed by a molar equivalent amount of allyl chloride to produce apolymer predominantly having the following structural formula:

CH CH (CH )CH i-CH{ CH CH CH OCH CH I CH2 C C CH H EXAMPLE 8 PreparationOf Polystyrene Terminated With Methacrylyl Chloride A stainless steelreactor is charged with 32 gallons of A.C.S. grade benzene(thiophene-free), which had been predried by Linde molecular sieves andcalcium hydride. The reactor is heated to a temperature of between38-40C and ml. of diphenyl ethylene is added to the reactor by means ofahypodermic syringe. An 1 1.4 percent solution of secondary butyl lithiumin hexane is added to the reactor portionwise until the retention of apermanent orange-yellow color is obtained (60 ml.), at which point anadditional 3.44 pounds of the secondary butyl lithium in hexane is addedto the reactor, followed by the addition of 82.5 pounds of purifiedstyrene over a period of 1 hour and 40 minutes. The reactor temperatureis maintained at 3840C. The living polystyrene is capped by the additionof0.28 pounds of ethylene oxide and the reaction solution changes from ared-orange color to yellow. The resulting capped living polystyrene isthereafter reacted with 260 ml. of methacrylyl chloride and the solutionchanges to a very pale yellow color. The methacrylate terminatedpolystyrene is precipitated by the addition of the polymer benzenesolution into methanol, whereupon the polymer precipitates out ofsolution. The polymer is dried in an air circulating atmosphere drier at40-45C and then in a fluidized bed to remove trace amounts of methanol.The molecular weight of the polymer as determined by membrane phaseosmometry, is 13,400 and the molecular weight distribution is verynarrow, i.e., the Mw/Mn is less than 1.05.

EXAMPLE 9 Preparation Of Polystyrene Terminated With Maleic Anhydride Astainless steel reactor is charged with 2.5 liters of A.C.S. gradebenzene (thiophene-free), which had been predried by a Linde molecularsieve and calcium hydride. The reactor is heated to 40C and 0.2 ml. ofdiphenyl ethylene is added to the reactor by means of a hypodermicsyringe. A 12.1 percent solution of secbutyl lithium in hexane is addedto the reactor portionwise until the retention of a permanentorange-yellow color is obtained (0.7 ml. at which point an additional22.3 ml. of sec-butyl lithium solution is added, followed by theaddition of 421.7 grams of styrene over a period of 16 minutes. Thereactor temperature is maintained at 4045C. Five minutes after styreneaddition is completed, ethylene oxide is added from a lecture bottlesubsurface intermittently until the solution is water white. One hourafter ethylene oxide addition is complete, 20.55 ml. of maleicanhydridebenzene solution (the maleic anhydride solution was prepared bydismatography.

solving 84 grams of maleic anhydride in 550 grams of purified benzene)is added to the capped living polymer. One hour after the addition ofthe maleic anhydride solution, the contents of the reactor aredischarged and precipitated in methanol. The maleic half esterterminated polystyrene had a molecular weight of about 14,000, asdetermined by Gel Permeation Chro- The polymerizable macromolecularmonomer has a structural formula represented as fol- Chloride C.P. grade1,3-butadiene (99.0 percent purity) is condensed and collected in l-pintsoda bottles. These bottles had been oven baked for 4 hours at 150C,nitrogen purged during cooling, and capped with a perforated metal crowncap using butyl rubber and polyethylene film liners. These bottlescontaining the butadiene are stored at l0C with a nitrogen pressure head10 psi) in a laboratory freezer before use. Hexane solvent is charged tothe reactors and heated to C, followed by the addition of 0.2 ml. ofdiphenyl ethylene by way of a syringe. Secondary butyl lithium is addeddropwise via syringe to the reactor until the red diphenyl ethyleneanion color persists for at least about 10-15 minutes. The reactortemperature is lowered to 0C, and 328.0 grams of butadiene is chargedinto the polymerization reactor, followed by the addition of 17.4 ml.(0.02187 mole) of a 12 percent secondary butyl lithium solution inhexane, when half of the butadiene charge has been added to the reactor.The butadiene is polymerized for 18 hours in hexane at 50C. Followingthe polymerization, 400 ml. portions of the anionic polybutadienesolution in the reactor is transferred under nitrogen pressure intocapped bottles. Allyl chloride (0.48 ml., 0.00588 mole) is injected intoeach of the bottles. The bottles are clamped in water baths attemperatures of 50C and C for periods of time ranging up to 24 hours.The samples in each of the bottles are short stopped with methanol andlonol solution and analyzed by Gel Permeation Chromatography. Each ofthe samples is water white and the analysis of the Gel PermeationChromatography scans reveals that each of the samples had a narrowmolecular weight distribution.

Several comparison samples were conducted in bottles coming from thesame lot of living polybutadiene, which were capped with 2-chlorobutane(0.4 mL, 0.00376 mole) as the terminating agent. The resulting polymersterminated with 2-chlorobutane were yellow in color and after standingfor a period of 24 hours at 70C, appeared to have a broad molecularweight distribution as revealed by the Gel Permeation Chromatographyscan. It is clear that the reaction and reaction EXAMPLE 1 1 PreparationOf Methacrylate Terminated Polyisoprene A one-gallon Chemco glass-bowlreactor is charged with 2.5 liters of purified heptane which had beenpredried by a Linde molecular sieve and calcium hydride,

followed by the addition of0.2 ml. of diphenyl ethylene as an indicatorand the reactor is sterilized with the dropwise addition of tertiarybutyl lithium solution (12 percent in hexane) until the retention of thecharacteristic light yellow color is obtained. The reactor is heated to40C and 19.9 ml. (0.025 mole) ofa 12 percent solution of tertiary butyllithium in hexane is injected into the reactor via hypodermic syringe,followed by the addition of 331.4 grams (4.86 moles) of isoprene. Themixture is allowed to stand for one hour at 40C and 0.13 mole ofethylene oxide is charged into the reactor to cap the livingpolyisoprene. The capped living polyisoprene is held at 40C for 40minutes, whereupon 0.041 mole of methacrylyl chloride is charged intothe reactor to terminate the capped living polymer. The mixture is heldfor 13 minutes at 40C, followed by removal of the heptane solvent byvacuum stripping. Based upon the Gel Permeation Chromatography scans forpolystyrene, the molecular weight of the methacrylate terminatedpolyisoprene by Gel Permeation Chromatography was about 10,000 (theory:13,000). The methacrylate terminated polyisoprene macromolecular monomerhad a structural formula represented as follows:

CHCH

(a1 CH A one-gallon Chemco glass-bowl reactor is charged with 2.5 litersof purified heptane which had been predried by a Linde molecular sieveand calcium hydride, followed by the addition of 0.2 ml. of diphenylethylene as an indicator. The reactor and solvent are sterilized by thedropwise addition of tertiary butyl lithium solution (12 percent inhexane) until the retention of the characteristic light yellow color isobtained. The reactor is heated to 40C and 19.03 ml. (0.02426 mole) oftertiary butyl lithium solution is injected into the reactor viahypodermic syringe, followed by the addition of 315.5 grams (4.63 moles)of isoprene. The polymerization is permitted to proceed at 50C for 66minutes and at this time 2.0 ml. (0.02451 mole) of allyl chloride is GHOG added to the living polyisoprene. The terminated polyisoprene is heldat 50C for 38 minutes, whereupon the polymer is removed from the reactorto be used in copolymerization reactions. The polymer was analyzed byGel Permeation Chromatography and had a very nar-' row molecular weightdistribution, i.e., and Mw/Mn of less than about 1.06. The theoreticalmolecular weight of the polymer is 13,000. The polymerizablemacromolecular monomer had a structural formula represented as follows:

EXAMPLE l3 Polymerization of Styrene With Vinyl Lithium To a l-gallonChemco reactor, there is added 2500 ml. of tetrahydrofuran and cooled to15C., at which time 6.5 ml. ofa 1 1.2 percent of vinyl lithium intetrahydrofuran (0.2 mole lithium) is added to the reactor, imparting alight tan color to the solution. The vinyl lithium was purchased fromAlpha lnorganics Ventron of Beverly, Massachusetts, as a two molarsolution in tetrahydrofuran. Analysis of the solution by several methodsshowed that the solution contained 1 1.2 percent active lithium. vinyllithium solution is added, a 0.25 mole styrene charge is added to thereactor via syringe with the observation of a small exotherm of about 1C(the reactor temperature is controlled by liquid nitrogen cooling coilsinside the reactor at a temperature of 15C). Ten minutes after thestyrene is added, 3.6 ml. of water is added to the reactor, resulting inan almost immediate change in color from deep orangebrown to water whiteand a considerable gas evolution is observed (the internal pressure inthe reactor increased from 8 psig to 12 psig). A sample is taken fromthe head space (about 2.5 liters in volume) and from the liquid phase atthe same time (the two samples are analyzed and identified as containinglarge amounts of ethylene). The styrene polymer is withdrawn from thereactor and analyzed. The GPC molecular weight of the polystyrene is108,000, as measured against the Pressure Chemical Company sample 2(b)standard certified as Mw/Mn 1.06, Mw 20,800 i 800 and Mn 20,200 2': 600.Measured against the same standard, the weight average molecular weightof the polymer is 99,000 and the number average molecular weight is66,000. The polydispersity of the polymer is 1.49. Based upon thelimiting polydispersity of about 1.33 for living polymers, as indicatedin Henderson et a1, Macromolecular Reviews, Vol. 3, lntersciencePublishers, page 347 (1968). several side reactions obviously occur whenusing vinyl lithium as a polymerization initiator. In addition, thebroad molecular weight distribution and the inability to control themolecular weight of the polymer is indicative that the initiation rateof vinyl lithium is extremely slow. Accordingly, the vinyl lithiuminitiated polystyrene is not suitable in the preparation of the graftcopolymers of the present invention in preparing chemically joined,phase separated graft copolymers, which have sidechains of controlledand uniform molecular weights.

Attempted copolymerization of the vinyl lithium initiated polystyrenewith methyl methacrylate and acrylonitrile under free-radical conditionsonly results in a mixture of polystyrene and the respective poly(methylmethacrylate) or polyacrylonitrile. Also, attempted copolymerization ofthe alpha-olefin terminated polystyrene of Example 1(a) with methylmethacrylate and acrylonitrile under free-radical conditions onlyresulted in a mixture of homopolymers as determined by IR analysis ofthe benzene and cyclohexane extracts. This result is expected due to theinability of alpha-olefins to polymerize under free-radical conditions.

Preparation Of Graft Copolymers Having Macromolecular Monomerslntegrally Polymerized Into The Backbone EXAMPLE 14 Preparation Of GraftCopolymer From Poly(alpha-methylstyrene) Macromolecular MonomerTerminated With Allyl Chloride And Ethylene A solution of grams ofpoly(alpha-methylstyrene) macromolecular monomer terminated with allylchloride and having an average molecular weight of 10.000 prepared as inExample 2(a) in 100 ml. of cyclohexane is prepared and treated with 5.5ml. of 0.645 M (9.1 percent solution) diethyl aluminum chloride inhexane and 2 ml. of vanadium oxytrichloride. then pressured withethylene to 30 psig. This system is agitated gently for about 1 hour at30C whereupon a polymeric material precipitates from the solution. It isrecovered by filtration and pressed into a thin transparent film whichis tough and flexible.

EXAMPLE 15 (a) Preparation Of Graft Copolymer Having A PolyethyleneBackbone And Polystyrene Sidechains:

One gram of the alpha-olefin terminated polystyrene of uniform molecularweight prepared in Example 1(a) is dissolved in 1500 ml. of cyclohexaneand charged into a 2-liter Chemco" reactor. The reactor is purged withprepurified nitrogen for 30 minutes, and 22 ml. of 25 percentethylaluminum sesquichloride solution (in heptane) is added. Thereaction is pressured to 40 psi with 20 grams of ethylene into thesolution. Thereafter, 0.1 ml. of vanadium oxytrichloride is added andthe ethylene pressure drops from 40 psi to 1 psi in about 1 minute. Thereaction is terminated in 3 minutes by the addition of isopropanol. Thepolymer is recovered by filtration and slurried with cyclohexane andthen with isopropanol. The yield is 18.0 grams of a fluffy, whitecopolymer having a macromolecular monomer sidechain content of 5.8percent, as determined by IR. Extraction and analysis of the extractsindicate all of the macromolecular monomer and 17.0 grams of theethylene copolymerized.

b. The procedure in Example 15 (a) is repeated, except that 2.0 grams ofthe macromolecular monomer is used instead of 1.0 gram. The yield of thecopolymer is 20.5 grams and the macromolecular monomer sidechaincontent, as determined by l.R., is 10 percent.

EXAMPLE 16 (a) Preparation Of Graft Copolymer Having A PolyethyleneBackbone And Polystyrene Sidechains:

A 2-liter Chemco" reactor is charged with 1500 ml. of purifiedcyclohexane. 20 grams of alpha-olefin terminated polystyrene prepared inExample 1(a) is added and dissolved in the purified cyclohexane. Thereactor is thereafter purged with prepurified nitrogen for one hour withconcurrent slow agitation-Ethylene is added to the reactor at the rateof 5 liters per minute to a pressure of 5 psi. The contents of thereactor is heated and controlled at 25C, and high speed stirring isstarted; ethylaluminum sesquichloride (22.8 ml., 25 percent in heptane)catalyst is injected into the reactor by a hypodermic syringe, followedby the addition of 0.1 ml. of vanadium oxytrichloride. Polymerizationbegins immediately and the ethylene pressure in the reactor drops tonearly zero in about a minute. At this point, the ethylene rate isreduced to 0.5 liter per minute, and cooling is used to maintain atemperature of 25C. At the end of one hour, a total of 43 grams ofethylene has been charged into the reactor, and the reactor is full of afluffy polymer slurry. The reaction is stopped by the addition of 50 ml.of isopropanol to inactivate the catalyst.

The polymer is recovered by filtration, slurried and boiled in 1.5liters of benzene for one hour. then refiltered to remove all theunreacted alpha-olefin terminated polystyrene from the copolymer. Thepolymer is then slurried in 1.5 liters of isopropanol and 0.03 gram oflrganox 1010 anti-oxidant is added and then filtered and dried in avacuum oven at 50C. The yield is 49 grams of a fluffy, white copolymerhaving an alphaolefin terminated polystyrene content of 16 percent. asdetermined by LR. of a pressed film.

b. Preparation Of Graft Copolymer Having A Polyethylene Backbone AndPoly (alpha-methylstyrene) Sidechains:

The macromolecular monomer used to produce the sidechains is firstprepared by repeating the procedure described in Example 2(a). exceptthat in place of the n-butyl lithium. 14 ml. (0.0178 mole) of sec-butyllithium (12 percent solution in heptane) is used as the initiator. Thenumber average molecular weight, as determined by gel permeationchromotography, is 26,000 (theory: 26.500) and the molecular weightdistribution is very narrow, i.e., the Mw/Mn is less than 1.05.

Four liters of cyclohexane (Phillips polymerization grade) and 200 gramsof the alpha-olefin terminated poly(alpha-methylstyrene) macromolecularmonomer produced as described above are charged into a Chemco reactor.The mixture is heated to C with concurrent stirring to dissolve themacromolecular monomer. The reactor is purged with high purity nitrogenfor one hour with stirring. Ethylene gas is introduced into the reactorto a pressure of 5 psi, followed by 228 ml. of ethylaluminumsesquichloride (25 percent in heptane) and 1.0 ml. vanadiumoxytrichloride. Agitation is increased and polymerization beginsimmediately, as noted by the pressure in the reactor dropping to nearlyzero. The ethylene flow rate is adjusted to 5 liters per minute, and theinternal temperature is controlled at 70C. At the end of one hour, thereaction is terminated by the addition of 500 ml. of isopropanol toinactivate the catalyst.

The polymer is isolated by centrifugation, slurried with benzene for onehour, and recentrifuged. The co-

1. from about 1 percent to about 95 percent by weight of polymerizablemacromolecular monomers having a substantially uniform molecular weightdistribution, and
 1. from about 1 percent to about 95 percent by weightof polymerizable macromolecular monomers having a substantially uniformmolecular weight distribution, and
 1. A polyblend comprising: A. fromabout 1 to about 50 parts by weight of a chemically joined, phaseseparated thermoplastic graft copolymer comprising:
 1. from about 1percent to about 95 percent by weight of polymerizable macromolecularmonomers having a substantially uniform molecular weight distributionsuch that their rAtio of Mw/Mn is less than about 1.1, and beingrepresented by the structural formula:
 1. A POLYBLEND COMPRISING: A.FROM ABOUT 1 TO ABOUT 50 PARTS BY WEIGHT OF A CHEMICALLY JOINED, PHASESEPARATED THERMOPLASTIC GRAFT COMPOLYMER COMPRISING:
 1. FROM ABOUT 1PERCENT TO ABOUT 95 PERCENT BY WEIGHT OF POLYMERIZABLE MACROMOLECULARMONOMERS HAVING A SUBSTANTIALLY UNIFORM MOLECULAR WEIGHY DISTRIBUTION,AND
 2. from about 99 percent to about 5 percent by weight of acopolymerizable comonomer comprising a comonomeric mixture of ethylacrylate and butyl acrylate, said comonomer forming the polymericbackbone of said graft copolymer and said polymerizable macromolecularmonomers forming linear polymeric sidechains of said graft copolymers,wherein a. said copolymerization of said polymerizable macromolecularmonomers and said copolymerizable comonomers occurs between themethacrylate polymerizable end group of said macromolecular monomers andsaid copolymerizable comonomer; and b. the linear polymeric sidechainsof the graft copolymers which are copolymerized into the copolymericbackbone are separated by at least about 20 uninterrupted recurringmonomeric units of said backbone polymer, the distribution and thecopolymerization of the sidechains along the backbone being controlledby the reactivity ratios of the methacrylate polymerizable end group onsaid macromolecular monomers and said copolymerizable comonomers; and B.from about 99 to about 50 parts by weight of a polymer of vinylchloride.
 2. FROM ABOUT 99 PERCENT TO ABOUT 5 PERCENT BY WEIGHT OF ACOPOLYMERIZABLE COMONOMER FORMING THE POLYMERIC BACKBONE OF SAID GRAFTCOPOLYMER AND SAID PILYMERIZABLE MACROMONOMER MONOMERS FORMING LINEARPOLYMEROC SODECHAINS OF SAID GRAFT COPOLYMER, WHEREIN: A. THE POLYMERICBACKBONES OF THE GRAFT COPOLYMER ARE COMPRISED OF POLYMERIZED UNITS OFSAID COPOLYMER ARE IZED COMONOMER, SAID COPOLYMERIZABLE COMONOMER BEINGAT LEAST ONE ETHYLENICALLY UNSATURATED MONOMER AND MIXTURES THEREOF: B.THE LINEAR POLYMERIC SIDECHAINS OF THE GRAFT COPOLYMER ARE COMPRISED OFCOPOLYMERIZED MACROMOLECULAR MONOMERS, SAID MACROMOLCCULAR MONOMERSCOMPRISING LINEAR POLYMERS OR COPOLYMERS HAVING A MOLECULAR WEIGHT INTHE RANGE FROM ABOUT 5,000 TO ABOUT 50,000 AND HAVING A SUBSTANTIALLYUNIFORM MOLECULAR WEIGHT DISTRIBUTION, SUCH THAT THEIR RATIO OF MW/MN ISLESS THAN ABOUT 1.1, SAID MACROMOLECULAR MONOMERS BEING FURTHERCHARACTERIZED AS HAVING NO MORE THAN ONE POLYMERIZABLE MOIETY PER LINEARPOLYMER OF COPOLYMER CHAIN, SAID COPOLYMERIZATION OCCURRING BETWEEN THEPOLYMERIZABLE ENG GROUP OF SAID MACROMOLECULAR MONOMERS AND SAIDCOPOLYMERIZABLE COMONOMER; AND C. THE LINEAR POLYMERIC SIDECHAINS OF THEGRAFT COPOLYMER WHICH ARE COPOLYMERIZED INTO THE COPOLYMERIC BACKBONEARE SEPARATED BY AT LEAST ABOUT 20 UNUNTERRUPTED RECURRING MONOMERICUNITS OF SAID BACKBONE POLYMER, THE DISTRIBUTION AND COPOLYMERIZATION OFTHE SIDECHAINS ALONG THE BACKBONE BEING CONTROLLED BY THE REACTIVITYRATIOS OF THE OLYMERIZABLE END GROUP ON SAID MACROMOLECULAR MONOMERS ANDSAID COPOLYMERIZABLE COMONOMER; AND B. FROM ABOUT 99 TO ABOUT 50 PARTSBY WEIGHT OF AT LEAST ONE OTHER POLYMER.--;
 2. The polyblend inaccordance with claim 1, wherein the polymerizable macromolecularmonomers of said graft copolymer are represented by the structuralformula:
 2. from about 99 percent to about 5 percent by weight of acOpolymerizable comonomer forming the polymeric backbone of said graftcopolymer and said polymerizable macromolecular monomers forming linearpolymeric sidechains of said graft copolymer, wherein: a. the polymericbackbones of the graft copolymer are comprised of polymerized units ofsaid copolymerized comonomer, said copolymerizable comonomer being atleast one ethylenically unsaturated monomer and mixtures thereof: b. thelinear polymeric sidechains of the graft copolymer are comprised ofcopolymerized macromolecular monomers, said macromolecular monomerscomprising linear polymers or copolymers having a molecular weight inthe range from about 5,000 to about 50,000 and having a substantiallyuniform molecular weight distribution, such that their ratio of Mw/Mn isless than about 1.1, said macromolecular monomers being furthercharacterized as having no more than one polymerizable moiety per linearpolymer of copolymer chain, said copolymerization occurring between thepolymerizable end group of said macromolecular monomers and saidcopolymerizable comonomer; and c. the linear polymeric sidechains of thegraft copolymer which are copolymerized into the copolymeric backboneare separated by at least about 20 uninterrupted recurring monomericunits of said backbone polymer, the distribution and copolymerization ofthe sidechains along the backbone being controlled by the reactivityratios of the polymerizable end group on said macromolecular monomersand said copolymerizable comonomer; and B. from about 99 to about 50parts by weight of at least one other polymer.--;
 2. from 99 percent toabout 5 percent by weight of a copolymerizable comonomer, saidcopolymerizable comonomer forming the polymeric backbone of said graftcopolymer and said polymerizable macromolecular monomers forming linearpolymeric sidechains of said graft copolymer, wherein: a. the polymericbackbones of the graft copolymer are comprised of polymerized units ofsaid copolymerizable comonomers, said copolymerizable comonomerscomprised of ethylenically saturated monomers containing at least onevinylidene
 3. The polyblend in accordance with claim 1, wherein thepolymerizable macromolecular monomers of said graft copolymer aremethacrylate terminated polydienes having a molecular weight in therange of from about 5,000 to about 50,000.
 4. The polyblend inaccordance with claim 1, wherein the polymerizable macromolecularmonomers are represented by the structural formula:
 5. The polyblend inaccordance with claim 1, wherein the polymerizable macromolecularmonomers are represented by the structural formula:
 6. The polyblend inaccordance with claim 1, wherein the copolymerizable comonomer of saidgraft copolymer is methyl methacrylate.
 7. The polyblend in accordancewith claim 1, wherein the copolymerizable comonomer of said graftcopolymer is acrylonitrile and comonomeric mixtures thereof.
 8. Thepolyblend in accordance with claim 1, wherein the copolymerizablecomonomer is vinyl chloride.
 9. The polyblend in accordance with claim1, wherein the copolymerizable comonomer is a comonomeric mixture ofethyl acrylate and butyl acrylate.
 10. The polyblend in accordance withclaim 1, wherein said other polymer (B) is a member selected from thegroup consisting of polymers of vinyl chloride, methyl methacrylate,acrylonitrile, styrene, copolymers and mixtures thereof.
 11. Thepolyblend in accordance with claim 1, wherein said other polymer (B) isa polymer of vinyl chloride.
 12. The polyblend in accordance with claim1, wherein said other polymer (B) is a polymer of methyl methacrylate.13. The polyblend in accordance with claim 1, wherein said other polymer(B) is a polymer of styrene and Copolymers thereof.
 14. The polyblend inaccordance with claim 1, wherein said other polymer (B) includes twopolymers blended with said graft copolymer.
 15. A polyblend comprising:A. from about 1 to about 50 parts by weight of a chemically joined,phase separated thermoplastic graft copolymer comprising:
 16. Thepolyblend in accordance with claim 15, wherein the polymerizablemacromolecular monomers are represented by the structural formula: 17.The polyblend in accordance with claim 15, wherein the backbone polymerof said graft copolymer is derived from a comonomeric mixture of ethylacrylate and butyl acrylate.
 18. The polyblend in accordance with claim15, wherein said other polymer (B) is a polymer of vinyl chloride. 19.The polyblend in accordance with claim 15, wherein said other polymer(B) is a polymer of styrene or copolymer thereof.